Described herein are isolated polypeptides each containing one or more receptor-binding sites of toxin A (tcdA) of Clostridium difficile (Cd), nucleic acids encoding the polypeptides, and methods of using the polypeptides and nucleic acids.本發明係關於一種單離之多肽,其含有一或多種艱難梭狀芽孢桿菌(Cd)毒素A(tcdA)之受體結合區域。本發明亦關於編碼該等多肽之核酸,及該等多肽及核酸之使用方法。